Machinery such as table saws, drill presses, and milling machines are used to carry out various finishing operations, such as shaping, sizing or sanding of a variety of materials. The feeding of very lengthy or oversized materials will frequently pose some difficulties for the tool operators because the limited work support surfaces of such tools are generally of limited size. As a result, such oversize workpieces would usually require additional operator assistance to help support the outer end portions of such materials as they are being fed to the operating tool to ensure that the material is properly oriented for the machining operation to be carried out. Various types of support stands have been available for feeding such lengthy material stock. One such stand has a roller with a horizontal axis that provides for a rolling line contact generally perpendicular to the direction of movement of the work. Another type includes a plurality of closely spaced ball bearings mounted so that the work, such as a plywood sheet, is movable on the bearings with at least two directions of freedom of movement, i.e., longitudinal and lateral motion. Typically, the work stand is placed a predetermined distance from the machine and the height thereof is adjusted to approximately the height of the working surface of the machine to support the elongated or oversized material thereon.
Work support stands of the ball bearing type are disclosed in U.S. Pat. Nos. 1,251,881; 2,237,615; and 4,381,054, permits smooth movement of the workpiece in varying directions as it is being fed to the machine. With certain heavy materials which may have a soft outer surface subject to being easily marred, the fact that each of the ball bearings may be fabricated of hard steel and make only point contact with the work, there is a tendency for the material to be marred, as by grooves or indentations, as the workpiece is moved over the stand.
The work stand that includes a roller disposed upon a frame or vertical support, as disclosed in U.S. Pat. Nos. 3,083,806 and 4,039,679, provide for only unidirectional movement of the workpiece which is perpendicular to the axis of the roller. Although the roller type work support stand, because of its greater surface area of contact with a workpiece is less likely to mar the surface thereof, has the tendency to maintain the movement of the workpiece in a single direction and therefore assists the user to guide the material in the desired direction.
U.S. Pat. No. 2,818,092 discloses a universal work support characterized by a plurality of pivotable castors. This patent purports to have almost the same advantages and capabilities as the ball bearing work stand without causing the contacting surface of the material to be marred as by grooves or indentations being caused by movement of the material on top of the castor wheels. To ensure smooth operation, it is essential that the castor wheels be aligned with the direction of movement of the material thereacross. In that connection, any hitch in the pivotable movement of the wheels can result in a drag on the material being moved thereover.